Changes in protein synthetic patterns during the various stages of spermatogenesis will be performed by in vivo labelling, separation of germ cells by Elutriation, and isolation of specfic proteins. Phosphoglycerate kinase (PGK) 1 and 2 will be purified with specific antisera and by affinity chromatography. Glucose-6-phosphate dehydrogenase (G6PD) will be isolated with antisera, by affinity chromatography, and further methods to be developed. Many proteins will be studied by two-dimensional gels. The t-allele related protein, p6.3/69, will be studied by the latter method. Functional assays of mRNA for these and other proteins will be performed on separated testicular cells using the rabbit reticulocyte, in vitro translational assay. RNA will be purified using the guanidinium thiocyanate or chloroform procedures. Proteins will be characterized as above; protamine-like histone will be isolated by electrophoresis on acid, urea gels and/or immunoprecipitation. X-inactivation during spermatogenesis will be studied by studying the synthesis of PGK-1 and G6PD during spermatogenesis in normal males and Sxr,XX "males".